[ESP LCD Touch CST816S Controller] Freeze while trying to read id using ESP32C6 and releasev5.1 (BSP-404)

[MohammedBENHADINE]

Hello,

Before opening this issue, I've tried two base codes to get CST816S working : esp-watch from esp-bsp and T display S3 both codes doesn't seem to work with my ESP32C6 and LCD TFT setup.
The LCD works fine and displays whatever you instructs it to show with LVGL.
But once I configure the CST816S driver the MCU stucks at doing its first hadnshake with the driver, at id reading.
I've made a minimal code (without this driver) to test the hardware wiring and i'm able to notice INT interrupts when I touch the screen and I'm also able to get the ID with this command :
`static void id_register_read(uint8_t addr)
{
uint8_t data[2];

i2c_master_write_read_device(0, 0x15, &addr, 1, data, 1, 1000 / portTICK_PERIOD_MS);
ESP_LOGI(TAG, "WHO_AM_I = %X", data[0]);

}`

Following up the issue with the library I ended up seeing the freeze/blocking at this function
esp_err_t panel_io_i2c_rx_buffer(esp_lcd_panel_io_t *io, int lcd_cmd, void *buffer, size_t buffer_size)
in esp_lcd/src/esp_lcd_panel_io_i2c.c file.

I've this minimal code to debug this issue :

#include <stdio.h>
#include <inttypes.h>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "driver/i2c.h"
#include "esp_system.h"
#include "esp_err.h"
#include "esp_check.h"
#include "esp_log.h"
#include "esp_lcd_touch_cst816s.h"
#include "freertos/semphr.h"

static const char *TAG = "i2CTest";
#define CHIP_ID_REG         (0xA7)

static QueueHandle_t gpio_evt_queue = NULL;
static esp_lcd_touch_handle_t tp;   // LCD touch handle

static SemaphoreHandle_t touch_mux;

static void IRAM_ATTR touch_callback(esp_lcd_touch_handle_t tp)
{
    uint32_t gpio_num = 8;
    xQueueSendFromISR(gpio_evt_queue, &gpio_num, NULL);

    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
    xSemaphoreGiveFromISR(touch_mux, &xHigherPriorityTaskWoken);

    if (xHigherPriorityTaskWoken) {
        portYIELD_FROM_ISR();
    }
}

void i2c_init(void)
{
    const i2c_config_t i2c_conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = 19,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_io_num = 20,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = 400000
    };
    i2c_param_config(0, &i2c_conf);
    i2c_driver_install(0, i2c_conf.mode, 0, 0, 0);
}

static void reset(void)
{
        gpio_set_level(21, 0);
        vTaskDelay(pdMS_TO_TICKS(200));
        gpio_set_level(21, 1);
        vTaskDelay(pdMS_TO_TICKS(200));
}

static void id_register_read(uint8_t addr)
{
    uint8_t data[2];

    i2c_master_write_read_device(0, 0x15, &addr, 1, data, 1, 1000 / portTICK_PERIOD_MS);
    ESP_LOGI(TAG, "WHO_AM_I = %X", data[0]);

}

void app_main(void)
{
    printf("Hello world!\n");
    gpio_evt_queue = xQueueCreate(10, sizeof(uint32_t));
    touch_mux = xSemaphoreCreateBinary();

    i2c_init();

    esp_lcd_panel_io_i2c_config_t io_config = ESP_LCD_TOUCH_IO_I2C_CST816S_CONFIG();

    esp_lcd_touch_config_t tp_cfg = {
        .x_max = 240,
        .y_max = 280,
        .rst_gpio_num = 21,
        .int_gpio_num = 2,
        .levels = {
            .reset = 0,
            .interrupt = 0,
        },
        .flags = {
            .swap_xy = 0,
            .mirror_x = 0,
            .mirror_y = 0,
        },
        .interrupt_callback = touch_callback,
    };
    esp_lcd_panel_io_handle_t io_handle = NULL;
    esp_lcd_new_panel_io_i2c((esp_lcd_i2c_bus_handle_t)0 , &io_config, &io_handle);
    esp_lcd_touch_new_i2c_cst816s(io_handle, &tp_cfg, &tp);
    uint32_t io_num;
    for(;;) {
        if (xSemaphoreTake(touch_mux, 0) == pdTRUE) {
        esp_lcd_touch_read_data(tp); // read only when ISR was triggled
        uint16_t touch_x[1];
        uint16_t touch_y[1];
        uint16_t touch_strength[1];
        uint8_t touch_cnt = 0;
        bool touchpad_pressed = esp_lcd_touch_get_coordinates(tp, touch_x, touch_y, touch_strength, &touch_cnt, 1);
        ESP_LOGI(TAG, "touch pressed = %d , x = %u , y=%u", touchpad_pressed, touch_x[0], touch_y[0]);

     }
        if(xQueueReceive(gpio_evt_queue, &io_num, portMAX_DELAY)) {
            printf("GPIO[%"PRIu32"] intr, val: %d\n", io_num, gpio_get_level(io_num));
        }
    }
}

Please note that I've added a queue to see if the ISR generates the interrupts but I don't see them coming. The esp32c6 is lost in the id reading step in esp_lcd_touch_new_i2c_cst816s function.
Could you please provide me with some guidelines to debug this issue or resolve it.

Regards,
Mohammed

[Lzw655]

Hi @MohammedBENHADINE, I tested the newest v1.0.3 driver in esp32c6 and it worked well.

The drivers in esp-watch from esp-bsp were created a long time ago and are not well-maintained. Please try again with the latest drivers mentioned above.

[MohammedBENHADINE]

Hi @Lzw655 ,
Thanks for the quick reply.
I'm getting the same behavior with the newest version of the cst816s driver.
Now I wonder if the LCD has a different IC. The supplier gave me this source code but it's not usable from my ESP32C6.
The IC reference is CST816D , is that different from the CST816S ?
Some pictures of the display :

[Lzw655]

According to the provided code, the CST816D has the same I2C address and register address as CST816S. So the v1.0.3 driver should work with CST816D.

Can you share the whole project for me to test?

[MohammedBENHADINE]

Hey @Lzw655 ,
Sorry for the delay.
Here is my test repo : https://github.com/MohammedBENHADINE/cst816d_test

Regards

[MohammedBENHADINE]

After many tests I figured out that the issue was hardware based.
The IC has some manufacturing issue and after using another one the library worked fine.